Differences of fractalkine (FKN) levels at different time points after stroke onset depending on stroke severity (means ± SD). Asterisks indicate significant differences between the two groups mild (NIHSS ≤3) and moderate/severe strokes (NIHSS >3). Number signs below the error bars indicate significant differences between moderate/severe stroke patients and controls. Within-group comparisons of FKN levels between the 6-hour (h) value and follow-up time points: significant differences were detected for the group of patients with mild strokes between 6 h and 12 h (P<0.001), 6 h and 24 h (P = 0.003), 6 h and 3 days (d) (P<0.001). For patients with moderate/severe strokes, significant differences were detected between 6 h and 24 h (P = 0.006), 6 h and 3 d (P<0.001), 6 h and 7 d (P<0.001) and 6 h and 90 d (P = 0.027).